My happs 3" TBs started out with the burring, but has quited down a lot over time.
FWIW, my original only got better after I "gently but firmly" constantly pressed down on the ball while rolling it in a circle. My kensington TB instructions said to do this to help break in the bearings (& rollers). If you try this, do
NOT put your whole weight on it; about 10-15 lbs presure should do, and keep moving the ball for 1-2 minutes. I could feel a minute bump/bend in one of the rollers when I first did this: I guess the pushing and rolling speeded up the roller's wear a little, and wore out the bump. OTOH, the two I built (mostly from parts from BobRoberts) started really bad, worse than my happs built one, but improved mostly after lightening the six case screws a little. Doing the presure roll on them didn't result in a noticable change.
And even with the burring, my first happs had a longer roll then the betson (barely) or wico (a lot). [sigh] One of these days I'll actually finish all my TB CPs, and my cab with changable CPs, ... and update analog+, and....
